O R I G I N A L A R T I C L E
Effects of Physical Activity Program on cognitive function and
sleep quality in elderly with mild cognitive impairment: A
randomized controlled trial
Kerime Bademli PhD
1|
Neslihan Lok PhD
2|
Muammer Canbaz PhD
3|
Sefa Lok PhD
41
Department of Psychiatric Nursing, Faculty of Nursing, Akdeniz University, Antalya, Turkey
2
Department of Psychiatric Nursing, Faculty of Health Sciences, Selçuk University, Konya, Turkey
3
Departmant of Physical Education and Sports, Selçuklu Anatolian School, Dumlupınar University Institute of Health Sciences, Konya, Turkey
4
Departmant of Coacing, Faculty of Sport Sciences, Selçuk University, Konya, Turkey Correspondence
Kerime Bademli, PhD, Department of Psychiatric Nursing, Faculty of Nursing, Akdeniz University, Dumlupınar Boulevard Campus Antalya 07058, Turkey. Email: kerimedemirbas@akdeniz.edu.tr
Abstract
Aim: The aim of this study is to determine the effect of a 20
‐week Physical Activity
Program for elderly individuals with mild cognitive impairment (MCI) on their
cognitive functions and sleep quality.
Methods: A randomized controlled trial research design was used in this
experimental pretest
‐posttest study. The data were analyzed using SPSS 21.0.
Results: This study showed that the Physical Activity Program improved the cognitive
functions and sleep quality of elderly individuals (p < 0.05).
Conclusion and Practice Implications: The findings of this study showed that the
cognitive functions and sleep quality of elderly individuals improved thanks to a
20
‐week Physical Activity Program. It is recommended that physical activities should
be included in nursing interventions for elderly people with MCI.
K E Y W O R D S
cognitive function, elderly, mild cognitive impairment, physical activity, sleeps quality
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I N T R O D U C T I O N
Aging is a universal phenomenon associated with deteriorating health status, and old age is often associated with increased health problems. With increasing age, older adults’ cognitive ability declines. Research shows declining ability in working memory, long‐term memory.1 The prevalence of all types of cognitive impairment, including dementias, increased with age. Age‐related cognitive decline is a growing public health concern worldwide. Mild cognitive impairment (MCI) is a syndrome that is defined as the expected cognitive decline depending on the individual’s age, but does not interfere significantly with the activities of daily living.2People with a mild version may demonstrate changes in their cognitive functions, but without affecting their daily activities. More than a quarter of older adults with cognitive impairment experience sleep distur-bance.3–6A study examining the epidemiology of sleep disturbances in the elderly found that the rate of sleep disturbances in the elderly sometimes reaches up to 50%.7 Another study conducted by Gooneratne and Vitiello8found that 20% to 40% of the elderly complain about insomnia symptoms. In a study conducted by
McKinnon et al,9 63% of patients with MCI were found to demonstrate sleep disturbance.
Some studies reported relationships between cognitive per-formance and sleep quality.10–13 On the other hand, the other studies showed that poor sleep in elderly is related to impaired health status, low levels of physical activity, poor physical functioning, and an increase in chronic diseases.14,15A study on sleep quality in elderly reported that sleep problems are less common in individuals who perform exercises regularly.16A meta
‐ analysis study reported that exercise is an evidence‐based intervention to improve perceived and objective metrics of sleep in healthy individuals.17 Increasing physical activity has been suggested for improving sleep in older people in general. Studies pointed out individuals who were highly active had less risk of chronic disease, decline in cognitive capacity, and poor sleep quality.18,19Active aging includes healthy lifestyle behaviors and physical activity. The sedentary lifestyle of older adults may contribute to the decline in health that often accompanies aging. The maintenance of high physical function is one of the key factors for successful aging.20
Physical activity is necessary for elderly people to protect their health and maintain a high quality life. If the level of physical activity is linked to sleep quality, the co‐occurrence of sleep disturbance and physical inactivity important for cognitive function.21,22Physical activity is associated with a better sleep quality and less sleep disorder in elderly people with MCI.3Recent studies from our group indicate that increased levels of structured physical activity have positive effects on sleep and performance in older adults.3,21 Lower intensity exercise interventions, such as yoga,23tai chi qigong,512 weeks and pedometer‐ based walking exercise, and cognitive exercise program,24the aquatic exercise25have also improved self‐reported sleep quality in addition to cognitive function in older adults. Thus, it would be worthwhile to carry out a study on the aforementioned issues.
In this study the 20‐week “Physical Activity Program” included 10‐min of warm‐up activities as the initial segment, 20‐min of rhythmic exercises as the activity segment, 10‐min of cool down exercises as the final segment, and 40‐min of free walking time. A significant body of research has investigated the effects of physical activity on sleep. Results generally suggest that physical activity is beneficial for sleep; however, it is unclear how large these benefits are, and to which type and duration of exercise moderate these benefits. There are still many gaps in the available research regarding the effect of different physical activity on sleep quality and cognitive impairment of individuals older than 65 years. To our knowledge, there have been few randomized controlled studies on the effects of physical activity on sleep quality and cognitive performance of elderly. In the current randomized controlled study, we examine the effects warm‐up activities, rhythmic exercises, cool down exercises and free walking exercises on sleep, and cognitive functions. Twenty‐ week regular physical activity was arranged in accordance with the ergonomic and physiological structure of individuals older than 65 years. We hypothesize that 20‐week regular exercise will have beneficial effects on sleep and cognitive functions of the elderly.
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M E T H O D S
2.1 | Design and sample
This study was conducted as a randomized controlled trial using a pretest‐posttest design. It took place in a nursing home affiliated with the Ministry of Family and Social Policies. The study data were collected between June and October 2016. The sample of the study consisted of elderly people (Standardized Mini Mental Test 23‐24 score interval) with MCI who were living in the nursing home.
A total of 176 elderly people over 65 years old who are registered at the nursing home affiliated with the Ministry of Family and Social Policies constituted the population of the study. Sample size calculations revealed that 56 individuals would be required to significantly test effects sized d = 0.80,26when accepting an
α‐error <0.05 and aβ‐error margin of 0.2 (http://danielsoper.com/statcalc3/ calc.aspx?id=47). Because of the possibility that samples may be loss, the final sample consisted of 60 elderly people, including 30 participants each in the experimental group and the control group.
The inclusion criteria of this study were giving consent to participate in the study, being literate and registered at the nursing home, having MCI and obtaining scores between 5 and 21 from the Pittsburgh Sleep Quality Index (PSQI). The exclusion criteria were having a sensory disability, having a physical impairment or disability, which would affects the participation in the exercise, participating in a similar accompanying program, and not participating in at least five sessions of the 20‐week Physical Activity Program.
Age, sex, education level were dependent variables. Cognitive level, sleep quality level were independent variables.
2.2 | Randomization
The elderly people who agreed to participate in the study were selected randomly using the simple randomization method. The participants were assigned to the experimental (n = 30) and control groups (n = 30) using the website, http://www.randomizer.org/form. htm. The files of 176 elderly people were evaluated by the researcher in accordance with the criteria for inclusion in or exclusion from the sample, and 148 names were put into the randomization process (Figure 1). In terms of sociodemographic characteristics, sex, marital status, and education level showed no statistically significant differences between the experimental and control groups. This study was not blind because the same person collected the pretest and posttest data and conducted the 20‐week Physical Activity Program.
2.3 | Intervention
2.3.1 | Development of the Physical Activity
Program
Before the study was conducted, the content of the program was designed in line with the relevant literature. Physical Activity Program components and approaches to develop a physical activity prescription for elderly people and the capacity of the elderly to adapt to the physical activity were also decided according to the related literature.20,27,28
2.3.2 | Implementation of the Physical Activity
Program
Before implementing the program, Sociodemographic Data Form, Standardized Mini Mental State Examination (SMMSE), the PSQI scale were administered to the experimental and control groups. Elderly people in the experimental group were provided with the program by a psychiatric nurse and an associate professor in sports health science. The program was planned in accordance with ergonomics and the physiological characteristics of individuals older than 65 years. The 20‐week “Physical Activity Program” included 10‐minute of warm‐up activities as the initial segment, 20‐minute of rhythmic exercises as the activity segment, 10‐minute of cool down exercises as the final segment and 40‐minute of free walking.
Physical Activity Program was organized to be performed 4 days a week, and 3 days a week, 7 days a week activity.
Warming (10 minutes) is the mild bodily and mental activity of the muscles, joints, respiratory, and circulatory system performed at the beginning of the exercise session to get ready for active exercise. Rhythmic exercise (20 minutes) was the phase in which the exercise program was implemented. For this phase, moderate activities including 22 simple movements (3 to 6 metabolic equivalent (ME) were chosen to speed up the respiratory, circulatory, and locomotor systems, the phase was first started with the correct breathing, then continued with stretching and stamina exercises (repeating each muscle group 4 or more). The duration and intensity of 22 rhythmic exercise activities were chosen so that the elderly can do it. The ME level is measured for each exercise. The concept of the individual’s physical activity level is evaluated with ME. ME is the amount of oxygen that the body uses during physical activity on a unit in the calculation.
Cool down (10 minutes) exercises were performed to enable the lactic acids accumulated in muscles and blood to return to their normal levels quickly to lower gradually the heart rate and blood pressure, which increased after the activity program. The exercises were finished after 10 minutes of low intensity. All exercise sessions were conducted in the presence of researchers and special attention
was paid to the participation of the entire experimental group. There was no weekly assessment of the elderly individuals’ exercise performance, but the effect of the Physical Activity Program on their cognitive functions and sleep quality was assessed at the end of 20 weeks.
For walking (40 minutes), a suitable area was selected for the participants to walk easily with normal steps and in balance. This exercise should be performed in an appropriate time (apart from the appropriate time for the elderly, the weather conditions should be also appropriate, and the walking activity should be performed approximately 2 hours after the meals). Researchers actively parti-cipated in the Physical Activity Program and performed all move-ments with the elderly participants. During the walking exercise, all of the participants wore a pedometer and the number of their steps was recorded.
All of the practices in the 20‐week Physical Activity Program were first explained to each of the elderly people in the experimental group, then together with their own group, and the researchers ensured that the participants understood and adapted to the program. The elderly in the experimental group were divided into five groups of six persons. All of the activities in the program were performed as a group of individuals. The sessions were conducted by three researchers. During the implementation of the Physical Activity F I G U R E 1 CONSORT schema [Color figure can be viewed at wileyonlinelibrary.com]
Program, the psychiatric nurse had presession meetings with the elderly people. During each session, the psychiatric nurse performed physical activities with the participants. During each session, the associate professor in sports, health science showed how to perform these activities. At the end of the Physical Activity Program, SMMSE, The PSQI scale were administered to both physical activity and control groups. No application was made to the control group during the 20‐week program. They continued their daily routine activities. Following the intervention process, the Physical Activity Program was applied to the control group. There is no planned implementation of the control group. The experimental group did not interact with the control group during their activities.
2.4 | Data collection
Both groups completed a sociodemographic data form, and their pretest measurements were taken at the beginning of the study. At the end of Physical Activity Program, the posttest measurements were taken.
2.5 | Instruments
2.5.1 | Sociodemographic data form
This form includes nine questions developed by the researcher to determine the participants’ sociodemographic characteristics and medical history.
2.5.2 | Standardized Mini Mental State Examination
The SMMSE was developed by Molloy et al.29 The validity and reliability study of the Turkish version of the test was conducted by Güngen et al.30This test includes orientation, registration, attention calculation, recall, language tests, and structuring sections. Each question is scored 1. The highest possible score on the scale is 30, and the lowest is 0. Scores between 0 to 12, 13 to 22, and 23 to 24 indicate severe, moderate and MCI, respectively. A score between 25 to 30 indicates no cognitive impairment. The correlation (r = 0.99) andκ (0.92) values between the total scores obtained from the scale were found to be high.30The Standardized Mini Mental Test had a Cronbachα value of 0.86 in the current study.
2.5.3 | The Pittsburgh Sleep Quality Index
The PSQI is used to assess sleep quality. The PSQI was developed by Buysse et al.31 The PSQI provides a reliable, valid, and standard measurement of sleep quality. The scale consists of 24 questions. The total PSQI score ranges from 0 to 21. Total scores of 0 to 4 and 5 to 21 indicate good and poor sleep quality, respectively. The sleep quality of those with a total score less than or equal to 5 is rated as “good”, while a total score greater than 5 indicates poor sleep.31The correlation between the total scores obtained from the scale was
found to be r = 0.81.13. The current study found that the PSQI had a Cronbachα value of 0.78.
2.6 | Ethical considerations
The study protocol was approved by the Ethics Committee of Selcuk University Faculty of Medicine (number: 80462/17; decision number: 149). An institutional approval was received from the nursing home. All participants were given information about the name, aim, length, and type of the study, and each read the agreement form. Written informed consent was obtained from each of the participants before the data collection process and the implementation of the Physical Activity Program were initiated.
2.7 | Data analysis
The study data were analyzed using SPSS statistical package (version 21.0; SPSS, Inc, Chicago, IL). For the descriptive statistical analysis, numbers, percentages, means, and standard deviations were used. The Mann‐Whitney U test was used to compare the pretest‐posttest scale mean scores of the experimental and control groups. The Wilcoxon signed‐rank test was used to assess the pretest and posttest data of the experimental group and the control group within themselves. The Cronbach α coefficients were calculated for the reliability of the scale and its subdimensions.
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R E S U L T S
The comparison of the data obtained from the participants regarding their sociodemographic characteristics and disease properties showed that there was no statistical difference between the experimental group and the control group. The findings related to the participants’ sociodemographic characteristics and disease properties are shown in Table 1.
3.1 | Comparison of the cognitive functions of
elderly in the experimental and control groups
The postintervention mean SMMSE score of the control group decreased in comparison with their preintervention mean score, but this difference was statistically insignificant (P > 0.05). There was no significant difference between the mean Mini Mental State Examina-tion scores of the experimental group and the control group before the intervention (day 0).
The measurement performed after the Physical Activity Program indicated that the mean Mini Mental State Examination score of the experimental group was higher than that of the control group, and this difference was statistically significant (P < 0.05). The current study found no difference between the experimental and control groups in posttest measurements in terms of their cognitive function
levels (P < 0.05), but found a significant difference in posttest measurements (P < 0.05) (Table 2).
3.2 | Comparison of the sleep quality of elderly in
the experimental group and control group
There was no significant difference between the PSQI mean scores of the experimental group and the control group before the interven-tion (day 0). The study found that the mean scores of the individuals in the experimental group on the PSQI scale increased at the end of the intervention process (after 20 weeks) in comparison with the preintervention scores (day 0).
The PSQI questionnaire was administered before and after the 20‐week Physical Activity Program, and the difference between the scores on the questionnaire was examined. The Wilcoxon test was used to test the significance of the experi-mental and control group itself. The mean score of the patients with MCI in the experimental group was found to decrease at the
end of the program and the difference was found to be statistically significant (P < 0.05). This study also found that sleep levels of the elderly in the control group did not change significantly after the application, and the difference was not statistically significant (P > 0.05). The Mann‐Whitney U test was used for the comparison between the groups because the normal distribution did not match. There was no significant difference between the experimental group and the control group in terms of sleep quality (P > 0.05) and posttest measurements (P < 0.05) (Table 3)
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D I S C U S S I O N
In the current study, a 20‐week Physical Activity Program was administered for elderly individuals with MCI, and the effect of this program on their cognitive functions and sleep quality was assessed. The results of this study showed that the Physical Activity Program T A B L E 1 An analysis of the descriptive characteristics of elderly in the experimental group and the control group
Experimental group, n = 30 Control group, n = 30
Sociodemographic characteristics n % n % P Age 72.24 ± 7.16 70.67 ± 8.34 0.63 Sex Female 18 30.1 17 28.3 0.54 Male 12 19.9 13 21.7 Education level Primary education 20 33.2 16 26.6 0.37
High school or higher degree 10 16.6 14 23.6
Since there were <25 subjects included in observation, it was analyzed with Yates correctedχ2test.
T A B L E 2 The distribution of the cognitive functions of experimental and control groups
SMMSE Experimental group, n = 30, mean ± SD Control group, n = 30, mean ± SD U P
Baseline 23.27 ± 2.17 23.42 ± 1.07 4.500 0.27
Postintervention 26.542 ± 1.84 22.24 ± 1.15 3.250 0.001*
Z −0.257 −6.839
P* 0.001* 0.79
Abbreviations: SMMSE, Standardized Mini Mental State Examination; U, Mann‐Whitney U test; Z, Wilcoxon analysis. df = 2.
*P < 0.05.
T A B L E 3 The distribution of the sleep quality of experimental and control groups
PSQI Experimental group, n = 30, mean ± SD Control group, n = 30, mean ± SD U P
Baseline 13.04 ± 2.06 12.14 ± 2.46 12.500 0.72
Postintervention 4.04 ± 1.78 13.05 ± 2.34 2.450 0.001*
Z −1.086 −6.373
P* 0.001* 0.27
Abbreviations: PSQI, Pittsburgh Sleep Quality Index; U, the Mann‐Whitney U test; Z, Wilcoxon analysis, d.f. (“degree of freedom”):2. df = 2.
increased their cognitive functions and sleep quality. These findings directly support those from previous studies, physical activity interventions such as yoga,23 tai chi qigong,5 12 weeks and pedometer‐based walking exercise, and cognitive exercise pro-gram,24 aquatic exercise25 have also improved self
‐reported sleep quality in addition to cognitive function in older adults.
Goal‐oriented, planned, and structured Physical Activity Programs are known to have a positive effect on the cognitive functions of elderly individuals.32 In spite of this, there is limited information about the effects of Physical Activity Programs on the MCI among elderly individuals.33,34 Similar to this study, a randomized controlled study conducted by Nagamatsu et al26 examined the effects of a Physical Activity Program on the memory related to possible MCI and found that physical activity and cognitive functioning are further supported by the significant correlation. A prospective cohort study showed that regular physical activity has a significant protective effect on the risk of cognitive impairment.35 Moreover, a study also emphasized that moderate and high levels of physical activity were significantly associated with lower risks of Alzheimer disease and of dementia of any type.35In line with these findings, it can be stated that physical activity has a protective role against the development of dementia.
The present results indicate that a 20‐week program physical activity effective in improving sleep quality subjectively assessed by applying the Pittsburgh Questionnaires. This can be explained by the fact that physical activity regulates sleep patterns, and sleep positively affects cognitive functions. With increasing age, substantial changes occur in sleep quantity and quality, including those in slow‐ wave sleep, spindle density, and sleep continuity.36 Sleep distur-bances and cognitive impairment are common in older adults. A meta‐analysis study conducted by Heyn et al18 found that the exercise training increased cognitive function and positive behavior in people with dementia and related cognitive impairments. Mount-ing evidence points to a potential connection between sleep and cognitive function. However, a study conducted by Blackwell et al37 reported that objectively measured disturbed sleep was consistently related to poorer cognition, whereas total sleep time was not. This finding suggests that the disturbance of sleep, rather than its quantity, affects cognition.38In this study, the assessment of sleep quality was only subjective. Future studies with physical activity, cognitive improvement, and sleep quality are needed in objective assessment by polysomnography and actigraphy.
A meta‐analysis study examined the effect of physical activity on sleep quality found that regular physical activity had a significant effect on sleep quality.17 In this randomized controlled study, we examined the effects warm‐up activities rhythmic exercises, cool down exercises, and free walking exercises on sleep, and cognitive functions. Twenty‐week regular physical activity was arranged in accordance with the ergonomy and physiological structure of individuals older than 65 years. We may conclude that, regardless of the type of physical activity performed, regular moderate exercise improves sleep quality and cognitive function in the elderly. In sum, our study provides preliminary evidence that multiple benefits for sleep disturbance and cognitive functions can be observed after
20‐week of Physical Activity Program. However, the mechanisms behind how physical activity may differentially impact cognition and sleep remain unclear. Further longer‐term studies on physical activity, cognitive improvement and sleep quality are needed to corroborate these results.
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C O N C L U S I O N
Sleep disorders and the decline of cognitive functions are associated with the inactive lifestyles of elderly individuals. Elderly people who performed exercise regularly have been found to have better sleep quality and fewer sleep problems. According to this study’s findings, the cognitive functions and sleep quality of elderly individuals improved thanks to a 20‐week program of regular physical activity.
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L I M I T A T I O N S
This study includes a sample limitation since it was conducted with elderly people living in a nursing house. The study results cannot be generalized since the external validity was not ensured, but the results can contribute to the generalization. The most important limitation of this study was that the control group, which received no intervention was only used to compare the groups and assess the effect of this intervention.
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I M P L I C A T I O N S F O R N U R S I N G
P R A C T I C E
This study found that physical activity and exercise are associated with a better sleep quality and less sleep disorder in elderly people with MCI. Nurses play a vital role in providing elderly with MCI with education and support. It is important for clinical nurses to routinely screen the sleep quality of elderly individuals to deliver appropriate interventions. When interacting with elderly individuals with MCI, clinical nurses need to assess these individuals in terms of sleep quality and cognitive function. Physical activities are beneficial for the elderly with MCI and improve sleep quality and cognitive function. Nurses are major partners in caring for the elderly in general and in the facilitation of creative group activities in particular. The results of this study suggest that nursing interven-tions should include physical activities among elderly with MCI. Regular Physical Activity Programs should be used to improve the cognitive functions of elderly people and enhance their sleep quality in routine practices.
C O N F L I C T S O F I N T E R E S T
The authors declare that there are no conflicts of interest.
O R C I D
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How to cite this article: Bademli K, Lok N, Canbaz M, Lok S. Effects of Physical Activity Program on cognitive function and sleep quality in elderly with mild cognitive impairment: A randomized controlled trial. Perspect Psychiatr Care. 2019;55: 401‐408.https://doi.org/10.1111/ppc.12324
